Mimic diagram panel



Sept. 16, 1952 R. B. THORP 2,611,018

MIMIC DIAGRAM PANEL Filed June 28, 1950 '/'w/ J; @L'launnmmm nununufnmA A 7 f Figi.

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HIS ATTORNEY Patented Sept. 16, 1952 MIMIC D IAGRAM 'PANEL Roger Bennett Thorp, London,England, assigner to Westinghouse Brake andA Signal Limited Landon, England Company.

Application June 28, 195o, getraind .170,779

" In Greet'. einem Jane 24. 1949 This invention relates tolmirnic diagrampanels of the kind described in co-pending patent applicatiori No.. 88,008 in the names of L. H. Peter and E. A. Sheppard and has Vfor its object the provision of improved arrangements `-for illuminating Certain o f the `variable or, controlled repremeans orindividual 'rods'ot .transparent mata rial to one single' rod oftransparent material to which is supplied'light from' one or more light units, the arrangement being, such that light from each lightinit is transmitted by internal reflection through the sirig'l'l through yeach individual rod/to the stripsA or plates bearing the representations or symbols to be illuminated.

In one embodiment of the invention comprising a track diagram for a railway signalling system, the representation of the railway tracks which require to be illuminated includes one or more cross-overs. The representation of each cross-over comprises four separate sections, forming the arms of a letter X, and it is desired to illuminate simultaneously one or other of the pairs of sections forming the diagonally vopposite arms of the X in order to indicate which route, of which the cross-over forms a part, is set up.

It may also be desired to illuminate the sections with white light when the route is set up and with red light when that portion of the track is occupied by a vehicle. In accordance with the above mentioned prior application, each of the four sections would be illuminated separately 'rod and lthence .a claims.. Y (c1. in,

with its own light units, one white and one red I Figure l shows a representation on a track diagram panel of a cross-over, which may be part of a railway track layout Vrepresented on the panel as a whole; and

Figure 2 represents a plan view' along the line A-A.

Referring to the drawing, the cross-over is depicted onlthepanel-, whiohis preferably formed oiva suitable transparent 'materiaL by 'lines paintedfon its rear surface and abuttingv againstthis` surface, in such positions that they coincide- 1; with the painted -representationof the cross-over,

are ioiinstripsl, 2., 4, 5 of'similarmaterial-each having vone end out atan angleand abutting against/a diamond shaped'piece 3. 'Thelrear surface of each of: the four-strips `is'provlded with scribed4 lines Vor shallow grooves 'I which? become illuminated 'by internal reflection of light passed into vthe strips,as described inthe vaforementioned co-pending application, 'to vindicate vcer--I `tainftraillc"conditionsto the ksignalman for whose information the diagram panel Yis provided.

With va cressLover of 'the kind lillustratori/it `is"- desired :that when' the ystri-ps are illuminatedl` theyaalways belilluminated in pairs, either' Ito-- getherl with .4- or` Siftogether-V with 5. For the Ipur` pose-'offilluminating strips! and with either white` or vred light, two lampk holders 3, 9- are provided onek off'which contains a redi-iilterf-for' colouring the light therefrom.

A rod I0, II of transparent material extends from each light unit to a single rod I3 with one end of which they are held in butting engagement by a suitable ferrule I2. The other end oi the single rod I3 is similarly held in butting engagement with two individual rods I5, Ii leading to the ends of the strips I, 4 so that when one of the lamps is lit the light rays therefrom are transmitted by internal reflection through the rod Il and II connecting the light unit to the single rod I3, through the single rod and thence through both individual rods I5, I 6 to the two strips I, Il.

The strips I, 4 may be formed integral with the rods I5, I5 or may be held in butting engagement therewith. Similarly, rods I0, II, I3, I5 and I5 may all be formed in one piece. The corners Il, I3 where the light rays have to be deflected substantially at right angles to enter the strips I, 4 are preferably formed at an angle of approximately 45 to the strips to ensure as complete reflection as possible, and. if desired a suitable mark, not shown, may be placed over this point to prevent light rays not so reflected from passing through the panel. The other pair of strips 2, 5 are similarly dealt with and it will then be seen that four lamps only are required for this portion of the track diagram instead of the usual eight required hitherto.

It is evident that the invention is not limited to the arrangement above described by way` of example. For instance, more than two strips or 'plates may be simultaneously illuminated by butting more individual rods against the end of the single rod, or each individual rod may be split into two or more branches, each leading to a different strip or plate or each feeding the strip or plate at a diiferent point. Furthermore, more than two light units may be used or, alterna-l tively, but a single light unit may be employed for each group of simultaneously illuminated strips yor plates.

Having thus described my invention, what I lclaim is:

1. For a railway signalling system, a mimic -track. diagram panel depicting a cross-over cornprising, in combination, a sheet of transparent material; four strips or plates of transparent vmaterial in surface contact with said sheet and,

.each having delineated thereon a representation of one arm of said cross-over, said representation being adapted to be illuminated by internal reiiection of light within said strip or plate; a rst single rod of transparent material; a iirst pair of individual rods of transparent material in light transferring engagement with one end of said rst single rod and a diagonally opposed pair of said strips or plates; a second single rod of transparent material; a second pair of individual rods of transparent-material in lighttransferring engagement with one end of said second single rod the other diagonally opposed pair of said strips or plates; and means for at times illuminating the other end of said first single rod or said second single rod.

2. A mimic diagram panel comprising a sheet of transparent material having representations delineated on one surface thereof, a strip of transparent material having other representations delineated on one surface thereof adapted to be illuminated by internal reflection of light within said strip, a median portion of said strip being in surface contact with the rear surface of said sheet, the two ends of said strip being bent and extending to the rear of said sheet, a member of light-conducting material abutting the two ends of said strip in light transferring engagement therewith, and two individual sources of light in light transferring engagement with said light-conducting member, each of said light sources being adapted to illuminate said strip through both ends thereof.

3. In a mimic diagram panel, the combination comprising. a strip of transparent light-conducting material having a median portion with representations delineated thereon adapted to be illuminated by internal reflection of light, the two ends of said strip being bent and extending rearwardly of said median portion, a member of light-conducting material abutting the two ends of said strip in light transferring engagement therewith, and two individual sources of light in light transferring engagement with said lightconducting member, the light from each of said sources passing into said strip from both ends thereof.

ROGER BENNETT THORP.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,989,237 Lilly et al. Jan. 29, 1935 2,218,074 Smith Oct. 15, 1940 2,285,014 Rowe June 9, 1942 2,305,185 Merkel Dec. 15, 1942 2,317,472 Merkel Apr. 27, 1943 2,501,160 Clarke Mar. 2l, 1950 FOREIGN PATENTS Number Country Date 212,955 Switzerland Apr. l, 194i 640,488 Germany Jan. 6. 1937 

